The present invention relates to a lifter apparatus of variable geometry, for crops which are leaning over, intended to be adapted to any cutter bar of a harvesting machine.
Present conditions have lead farmers to seek diversification in their crops. Some crops do not present any problems, but others do, because they tend to lean over to a significant degree. This is true, for example, for leguminous plants, seed-bearing alfalfa, proteinaceous peas, and seed vetch; in graminaceous plants, it also applies to ryegrass, and fescue for seed production. All these plants must be systematically lifted as they are being harvested; this is a delicate operation, and the number of apparatuses thus far proposed to the user is certainly evidence that the present state of the art is not satisfactory.
This is the case with French Pat. No. 2 317 871, filed July 12, 1976. This very simple lifter affords no safety at all in terms of its function; it is not very well adapted to crops lying flat on the ground. Other lifters are more sophisticated, but they follow the irregularities of the ground poorly, and they are very vulnerable to breakage during their accidental encounters with the soil.
French Pat. No. 2 545 683, filed June 13, 1983, relates to a different kind of lifter, but a study of this patent, and reducing it to practice, confirms its fragility; it does not have a safety system, and its runner has to slide on dry, hard soil in order to make the part called a piston work; it does not permit locking the cutter bar at ground level, because the cylindrical tube is structurally fixed to the horizontal and vertical supports, and the part called the piston cannot function unless the harvesting machine is driven forward.
Moreover, although to prevent wear and breakage, it is not recommended that the lifters mentioned above be left permanently on the machine, it is imperative that the lifter of French Pat. No. 2 545 683 be removed again after use.